My 5.2L D has been rough starting since I bought it a week or so ago. I noticed that today when I try starting and it doesn't start the speedometer goes up from 0mph to around 35mph give or take while Its cranking. If I let off the key and try to start it again it will normally start right up without the speedo needle jumping its a little hesitant and Idles rough for a second but then idles fine. Is it normal for the Speedo to jump like that If not, what would cause that?

 

its definitely not normal for the speedo to jump, but idk what would cause it,

 

Yea Really, Its got me confused I will try doing a video later for a better idea.